Reading your reply you sound that you are doing incredibly well. Don’t think too far ahead, just day by day. You should be proud you can even go to work and endure those horrible xmas songs. You will get through this xmas and my only advice is don’t do New year. Go to bed early and avoid at all cost.
Your colleague who was left by her husband reminded me of my boss. She has the same happen to her and said to me it was worse for her as she had been rejected blah blah. So I replied well your children still have a father don’t they? I have learned to be tough and sound insensitive but this loss we’ve had is not up for comparison.